It heats. It powers. Is it the future of home energy?
Down in Bernard Malin’s basement is a softly thrumming metal box that turns natural gas into hot water and generates $600 to $800 worth of electricity a year — a bonus byproduct of heating his home.“It’s like printing money,” says Mr. Malin, the first person in Massachusetts — perhaps in the nation — to own a residential “micro combined-heat-and-power” system, also known as micro-CHP.
Since Malin changed his home heating system to micro-CHP in February, 18 other families in the Boston area also have adopted the technology, which squeezes about 90 percent of the useful energy from the fuel. That’s triple the efficiency of power delivered over the grid.
Factories and other industrial facilities have used large CHP systems for years. But until the US debut of micro-systems in greater Boston, the units had not been small enough, cheap enough, and quiet enough for American homes. Add to that the public’s rising concern about electric-power reliability — seen in a sales boom of backup generators in the past couple of years — and some experts see in micro-CHP a power-to-the-people energy revolution.
So, how does a micro-CHP squeeze out three times the efficiency of power delivered over the grid? It’s pretty simple once you realize what efficiency means: the fraction of energy input that you get out as useful work, rather than “useless” heat.
If you want heat, it’s remarkably easy to be efficient. Instead of generating unwanted heat at the power plant and along transmission lines, you generated wanted heat in a cold home in the winter.
I suppose the whole scheme falls apart in the summer.